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1.
Nat Commun ; 15(1): 4712, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38830888

RESUMO

Low-energy consumption seawater electrolysis at high current density is an effective way for hydrogen production, however the continuous feeding of seawater may result in the accumulation of Cl-, leading to severe anode poisoning and corrosion, thereby compromising the activity and stability. Herein, CoFeAl layered double hydroxide anodes with excellent oxygen evolution reaction activity are synthesized and delivered stable catalytic performance for 350 hours at 2 A cm-2 in the presence of 6-fold concentrated seawater. Comprehensive analysis reveals that the Al3+ ions in electrode are etched off by OH- during oxygen evolution reaction process, resulting in M3+ vacancies that boost oxygen evolution reaction activity. Additionally, the self-originated Al(OH)n- is found to adsorb on the anode surface to improve stability. An electrode assembly based on a micropore membrane and CoFeAl layered double hydroxide electrodes operates continuously for 500 hours at 1 A cm-2, demonstrating their feasibility in brine electrolysis.

2.
bioRxiv ; 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-37662334

RESUMO

Recurrent DNA break clusters (RDCs) are replication-transcription collision hotspots; many are unique to neural progenitor cells. Through high-resolution replication sequencing and a capture-ligation assay in mouse neural progenitor cells experiencing replication stress, we unraveled the replication features dictating RDC location and orientation. Most RDCs occur at the replication forks traversing timing transition regions (TTRs), where sparse replication origins connect unidirectional forks. Leftward-moving forks generate telomere-connected DNA double-strand breaks (DSBs), while rightward-moving forks lead to centromere-connected DSBs. Strand-specific mapping for DNA-bound RNA revealed co-transcriptional dual-strand DNA:RNA hybrids present at a higher density in RDC than in other actively transcribed long genes. In addition, mapping RNA polymerase activity revealed that head-to-head interactions between replication and transcription machinery resulted in 60% DSB contribution to the head-on compared to 40% for co-directional. Our findings revealed TTR as a novel fragile class and highlighted how the linear interaction between transcription and replication impacts genome stability.

3.
Nat Commun ; 15(1): 3594, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38678011

RESUMO

Recurrent DNA break clusters (RDCs) are replication-transcription collision hotspots; many are unique to neural progenitor cells. Through high-resolution replication sequencing and a capture-ligation assay in mouse neural progenitor cells experiencing replication stress, we unravel the replication features dictating RDC location and orientation. Most RDCs occur at the replication forks traversing timing transition regions (TTRs), where sparse replication origins connect unidirectional forks. Leftward-moving forks generate telomere-connected DNA double-strand breaks (DSBs), while rightward-moving forks lead to centromere-connected DSBs. Strand-specific mapping for DNA-bound RNA reveals co-transcriptional dual-strand DNA:RNA hybrids present at a higher density in RDC than in other actively transcribed long genes. In addition, mapping RNA polymerase activity uncovers that head-to-head interactions between replication and transcription machinery result in 60% DSB contribution to the head-on compared to 40% for co-directional. Taken together we reveal TTR as a fragile class and show how the linear interaction between transcription and replication impacts genome stability.


Assuntos
Quebras de DNA de Cadeia Dupla , Replicação do DNA , Instabilidade Genômica , Transcrição Gênica , Animais , Camundongos , Células-Tronco Neurais/metabolismo , DNA/metabolismo , DNA/genética , Origem de Replicação , Telômero/metabolismo , Telômero/genética , Centrômero/metabolismo , Centrômero/genética
4.
Environ Pollut ; 321: 121142, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36702430

RESUMO

Herein, polyethyleneimine (PEI)-grafted nitrogen-doping magnetic hydrochar (PEIMW@MNHC) was synthesized for hexavalent chromium (Cr(VI)) and bisphenol A (BPA) elimination from water. Characterizations exhibited that abundant amino functional groups, intramolecular heterocyclic N, azo and Fe-NX structures were successfully introduced into the inherent structure of hydrochar. The obtained PEIMW@MNHC presented maximum uptake of 205.37 and 180.79 mg/g for Cr(VI) and BPA, respectively, and was highly tolerant to various co-existing ions. Mechanism investigation revealed that the protonated amino, intramolecular heterocyclic N and Fe(II) participated in Cr(VI) reduction, and the N/O-containing groups and Fe(III) fixed Cr(III) onto PEIMW@MNHC by the formation of complexes and precipitates. On the other hand, azo, Fe-NX and graphitic N structures contributed to the removal of BPA via pore filling, hydrogen bonding and π-π interactions. Additionally, PEIMW@MNHC maintained over 85.0% removal efficiency for Cr(VI) and BPA after four cycles, manifesting that PEIMW@MNHC was an ideal adsorbent with outstanding practical application potential.


Assuntos
Polietilenoimina , Poluentes Químicos da Água , Polietilenoimina/química , Adsorção , Compostos Férricos , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio , Água/química , Cromo/química , Cinética , Fenômenos Magnéticos
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